Cold water supply apparatus

ABSTRACT

A multiplicity of water passage pipes (4) are received in a horizontal, cylindrical-shaped drum (3), which is provided at an upper portion thereof with a discharge port (3a) and an inflow port (3b) for a refrigerant. Fixed to both ends of the drum (3) are a water introduction cylinder (6) and a discharge cylinder (7), which is bent downward to be substantially L-shaped. A heat exchanger (1) is secured such that en end thereof on a side of the discharge cylinder (7) is disposed above a cold water tank (2). An interior of the cold water tank (2) is divided into a first tank (2a) and a second tank (2b) by a partition (8), over which water can flow. A piping for supplying a cold water to a facility for utilization of the cold water is connected to a bottom or a lower portion of the first tank (2a), on which the cold water from the heat exchanger (1) falls. A path for water recovery from the facility for utilization of the cold water is connected to the second tank (2b) through a return piping (11). The second tank (2b) is connected to a side of the water introduction cylinder (6) of the heat exchanger (1) through a cold water circulating pump (12). When water circulation for the heat exchanger (1) is stopped, water in the heat exchanger (1) is discharged to fall in the cold water tank (2), thereby preventing freezing.

TECHNICAL FIELD

The present invention relates to a cooling water supply apparatus forobtaining cooling water by performing heat exchange between water and acoolant circulating inside a heat exchanger.

BACKGROUND ART

Various types of cooling apparatuses that employ a coolant in the priorart include cooling water supply apparatuses for supplying cooling waterto factories, stores and the like. In such a cooling water supplyapparatus, water and the coolant are caused to circulate inside a heatexchanger so that by performing heat exchange between the coolant andthe water, cooling water can be obtained.

A heat exchanger employed in such a cooling water supply apparatusnormally adopts a structure in which piping is provided inside a drum.Since a chiller unit for cooling the coolant is connected to the drum,the coolant can circulate inside the drum. In addition, the piping isprovided in such a manner that water can flow inside and the dischargeside of the piping is connected to a path through which cooling water issupplied to a utilizing facility, such as a factory, a store or thelike.

Cooling water is created at the cooling water supply apparatus describedabove in the manner described below. Namely, coolant from the chillerunit is supplied into the drum of the heat exchanger and at the sametime, water is supplied into the piping. This places the coolant and thewater in contact with each other via the piping, and, as a result, theheat in the water in the piping is drawn out by the coolant around thepiping so that the water becomes cold. This cold water is delivered intothe supply path and is eventually utilized as cooling water at theutilizing facility.

However, the cooling water supply apparatus described above still posesthe problem described below that is yet to be addressed. Namely, sincethe circulation of water inside the heat exchanger is stopped during,for instance, night time when it is not necessary to supply coolingwater to the utilizing facility, which leaves residual water inside thepiping, the coolant and the still water remain in contact over a longperiod of time via the piping. Consequently, the water inside the pipingmay become frozen, disabling circulation of water when the operationrestarts or damaging the piping.

An object of the present invention which has been proposed to eliminatethe problem of the prior art discussed above, is to provide a coolingwater supply apparatus with which water can be prevented from becomingfrozen inside the heat exchanger after water circulation is stopped.

DISCLOSURE OF INVENTION

In the cooling water supply apparatus according to the present inventionwhich is provided with a heat exchanger in which a coolant and water cancirculate and a cooling water tank for storing cooling water obtained byperforming heat exchange between the coolant and the circulating waterinside the heat exchanger, the heat exchanger is positioned above thecooling water tank so that when the water circulation inside the heatexchanger is stopped, the water inside the heat exchanger drains intothe cooling water tank.

According to the present invention, since the water inside the heatexchanger drains into the cooling water tank when cooling water supplyis not required and the water circulation is stopped, the coolant andthe water are no longer in contact, thereby preventing the water fromfreezing. In particular, by forming a water discharge portion and awater intake portion at the heat exchanger in a downward direction,water discharge is effected by gravity, thereby eliminating thenecessity for providing a special motive force for water discharge.

In addition, the inside of the cooling water tank may be divided into afirst tank and a second tank with a partition, with the partition formedat a height which allows cooling water to overflow from the first tankto the second tank. Furthermore, the discharge portion through which thecooling water is discharged from the heat exchanger may be providedabove the first tank with the second tank connected to the intakeportion of the heat exchanger.

This structure allows cooling water that is at a relatively hightemperature in the upper portion of the first tank to overflow over thepartition into the second tank and to be taken into the heat exchangerthrough the intake portion to be cooled again and flow down into thefirst tank through the discharge portion so that cooling water can beobtained with a high degree of efficiency. In particular, by connectinga supply path for supplying the cooling water to the utilizing facilityto the first tank and connecting a return path through which the coolingwater that has been utilized at the utilizing facility returns to thesecond tank, the water whose temperature has increased through theutilization at the utilizing facility after it is supplied to theutilizing facility through the supply path from the first tank iscollected into the second tank via the return path. Consequently, thewater at high temperature that is collected does not directly mix withthe water in the first tank, which allows the water in the first tank tomaintain a low temperature at all times to achieve a supply of coolingwater whose quality is stable.

Moreover, a coolant tank where the coolant is temporarily stored after aheat exchange may be provided below the heat exchanger. Since thisstructure allows the coolant inside the heat exchanger to be dischargedand flow down into the coolant tank after the coolant circulation isstopped, the coolant and the water do not come into contact with eachother, thereby preventing freezing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating an embodiment of the cooling watersupply apparatus according to the present invention;

FIG. 2 is a partial cutaway side view of the drum in the embodimentillustrated in FIG. 1;

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a side elevation illustrating the intake cylinder in theembodiment illustrated in FIG. 1; and

FIG. 5 is a side elevation illustrating the discharge cylinder in theembodiment illustrated in FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

The following is an explanation of a specific embodiment of the presentinvention in reference to the drawings.

(1 Structure)

This embodiment comprises a pair of heat exchangers 1 that providecooling water by circulating water inside and a cooling water tank 2that stores the cooling water from the heat exchangers 1, as illustratedin FIG. 1. The structure of the heat exchangers 1 and the cooling watertank 2 are explained separately below.

(1--1) Structure of the heat exchanger

As shown in FIGS. 2 and 3, a plurality of water flow pipes 4 are housedinside a drum 3 which is formed in a lateral cylindrical shape in adirection parallel to the axis of the drum 3. The two ends of thecylindrical drum 3 are sealed off by lid plates 5. At the upper portionof the drum 3, a discharge port 3a and an inflow port 3b for a coolant(hereafter referred to as brine) are provided. Leg portions 3c areprovided at the lower portion of the drum 3.

In addition, the two ends of each water flow pipe 4 project out to theoutside of the two ends of the drum 3 through the lid plates 5. At thetwo ends of the drum 3, flanges 3d and 3e are provided. A waterintroduction cylinder 6 and a water discharge cylinder 7, as illustratedin FIGS. 4 and 5, are secured to the flanges 3d and 3e respectively. Theends of the water flow pipes 4 are exposed in the space inside theintroduction cylinder 6 and the discharge cylinder 7 so that a structurein which water supplied through the introduction cylinder 6 travelsthrough the water flow pipes 4 to be delivered into the space inside thedischarge cylinder 7 located on the opposite side of the drum 3 isachieved. It is to be noted that, as illustrated in FIG. 5, thedischarge cylinder 7 is formed in a shape which bends downward in arough L shape.

Furthermore, as shown in FIG. 1, which illustrates the overall structureof the apparatus, two heat exchangers 1 are provided parallel to eachother. The leg portions 3c of the drums 3 are secured to the upperportion of the cooling water tank 2 so that the ends of the two heatexchangers 1 toward the discharge cylinders 7 will be located above thecooling water tank 2.

Moreover, a chiller unit 13 for supplying cooled brine is connected tothe heat exchangers 1 structured as described above. Namely, the inflowport 3b and the discharge port 3a at the upper portion of each drum 3are respectively connected to an outflow port 13a and an inflow port 13bof the chiller unit 13 via piping. In addition, a brine pump 14 and anexpansion tank 15 are provided at the piping located toward the inflowport 13b.

(1--2 Structure of the cooling water tank)

At the center of the space inside the cooling water tank 2, a partition8 is provided to divide the space into a first tank 2a (the right sidein FIG. 1) and a second tank 2b (the left side in FIG. 1) to achieve atwo-tank structure. The upper portion of the partition 8 is set lowerthan the upper portion of the cooling water tank 2 so that cooling watercan overflow from the first tank 2a into the second tank 2b.

The first tank 2a is employed as a water supply tank for supplyingcooling water flowing down from the heat exchangers 1 to the utilizingfacility. Namely, piping for supplying cooling water that has beencooled at the heat exchangers 1 is connected to the bottom or the lowerportion of the first tank 2a. This piping is extended to the utilizingfacility such as a factory, a store or the like where the cooling wateris used via a cooling water supply pump 9.

The second tank 2b, on the other hand, is a collecting tank forcollecting water whose temperature has risen after being used at theutilizing facility. Namely, as illustrated in FIG. 1, a water feed port10 is provided at the first tank 2a of the cooling water tank 2. A watercollection path for collecting water that has been used at the utilizingfacility is connected to the water feed port 10. However, it is to benoted that the water feed port 10 is not in communication with the firsttank 2a, but is connected to the second tank 2b constituting thecollecting tank through a return piping 11 indicated with the bold linein FIG. 1.

Moreover, piping connected to the introduction cylinders 6 of the heatexchangers 1 is connected to the second tank 2b via a cooling watercirculating pump 12. Thus, a structure in which the water collected inthe second tank 2b is sent out to the heat exchangers 1 by the coolingwater circulating pump 12 and is cooled again by coming into contactwith the brine circulating the outer perimeter of the water flow pipes 4while it travels through the water flow pipes 4 of the heat exchangers 1is achieved.

(2 Functions)

The functions of the embodiment structured as described above are asfollows. First, the brine that has been cooled at the chiller unit 13 issupplied via the inflow ports 3b at the upper portions of the drums 3.It is assumed that the temperature of the brine to be supplied is setat, for instance, -7° C. The brine thus supplied draws out the heat fromthe water within the water flow pipes 4, resulting in its temperatureincreasing to, for instance, approximately -3° C. before it isdischarged through the discharge ports 3a. The brine thus discharged isreturned to the chiller unit 13 by the brine pump 14, cooled in the unitand is supplied again to the inflow ports 3b of the drums 3.

The water inside the second tank 2b, on the other hand, is supplied tothe water flow pipes 4 inside the heat exchangers 1 through theintroduction cylinders 6 by the cooling water circulating pump 12. Theheat in the water thus supplied is drawn out by the brine during theprocess in which the water travels through the water flow pipes 4, asexplained earlier, resulting in its temperature cooling down to, forinstance, approximately 1° C., before it is sent out toward thedischarge cylinders 7 on the opposite side of the drums 3. The dischargecylinders 7 of the heat exchangers 1 are located above of the first tank2a of the cooling water tank 2, with the discharge cylinders 7 bendingdownward, which allows the cooled water to flow down through thedischarge cylinders 7 into the first tank 2a.

Thus, in the first tank 2a, where the cooling water that has flowed downis collected, the cooling water whose temperature is relatively high iscollected in its upper portion and the cooling water whose temperatureis relatively low concentrates in the bottom portion, due to convectioncurrents in the water. Then, the cooling water at low temperature towardthe bottom of the first tank 2a is sent out by the cooling water supplypump 9 through the piping connected to the bottom or the lower portionof the first tank 2a to be supplied to the utilizing facility, such as afactory, a store or the like.

In addition, the cooling water at a relatively high temperature in theupper portion of the first tank 2a, which overflows over the partition 8into the second tank 2b, is delivered into the introduction cylinders 6by the cooling water circulating pump 12 again to be further cooled atthe heat exchangers 1.

Then, water whose temperature has increased to, for instance,approximately 16° C. after being used at the utilizing facility, iscollected into the second tank 2b via the water feed port 10 through thereturn piping 11, is delivered into the heat exchangers 1 by the coolingwater circulating pump 12 to be cooled again.

In order to halt the cooling water supply process described above, thecooling water supply pump 9, the cooling water circulating pump 12 andthe brine pump 14 are stopped. This will cut off water supply to thedrums 3 and, at the same time, the water inside the discharge cylinders7 bending downward and the water inside the water flow pipes 4communicating with the discharge cylinders 7 flow down into the firsttank 2a of the cooling water tank 2 by gravity, thereby emptying thewater passage pipes 4.

(3 Advantages)

The following advantages are achieved through the embodiment of thepresent invention. Namely, since the water passage pipes 4 are emptiedwhen the apparatus is stopped, the brine and the water do not remain incontact, thereby eliminating the risk of defective circulation due tofreezing and of damage to the piping.

In particular, since water flows down from the heat exchangers 1 intothe cooling water tank 2 by gravity, water can be automaticallydischarged without having to employ a special motive force so that atrouble-free water discharge process is realized while only requiring alow production cost for manufacturing the apparatus.

In addition, since cooling water at relatively low temperature insidethe first tank 2a is supplied to the utilizing facility and coolingwater at a relatively high temperature inside the first tank 2a isallowed to overflow into the second tank 2b to be guided into the heatexchangers 1 again, cooling water can be obtained with a high degree ofefficiency and cooling water at a stable low temperature can be suppliedto the utilizing facility at all times.

Furthermore, since water at high temperature that has been used at theutilizing facility and has been collected through the water feed port 10is supplied to the second tank 2b, it does not mix directly with thecooling water inside the first tank 2a. Consequently, only water thathas been fully cooled is supplied to the utilizing facility withoutreducing the cooling effect achieved by the heat exchangers 1.

Moreover, since cooling water is supplied via the cooling water tank 2rather than constituting a cooling water circulating path only withpiping, it is easier to support fluctuations in the demand for coolingwater. Particularly, even when a large quantity of cooling waterexceeding the cooling capability of the heat exchangers 1 is required,the demand for such a large quantity of cooling water can be satisfiedby sending out low-temperature water that has been stored in the firsttank 2a in advance.

(4) Other embodiments

The present invention is not limited to the example explained inreference to the embodiment presented above, and a number of variationsmay be conceived in regard to the shape, quantity, position, size andthe like of the individual members. For instance, the quantity and thesize of the heat exchangers 1, the water passage pipes 4 and the coolingwater tank 2 and the forming positions and the like of the brinedischarge ports 3a, the brine inflow ports 3b and the water feed port 10may be freely changed during the design stage.

In addition, both the introduction cylinders 6 and the dischargecylinders 7 described in reference to the embodiment above may be formedin a shape bending downward in an L shape so that when the watercirculation is stopped, the water inside the water passage pipes 4 flowsdown toward both the introduction cylinders 6 and the dischargecylinders 7 (toward the two ends of the drums 3) due to gravity. Thisstructure will allow the water inside the heat exchangers 1 to bedischarged even faster with an even higher degree of reliability. It isto be noted that when this structure is adopted, the position of thecooling water tank 2 located under the heat exchangers 1 may be adjustedto receive water flowing down from the two ends of the drums 3.

Alternatively, only the introduction cylinders 6 may be positioneddownward, or the drums 3 may be provided inclined toward either theintroduction cylinders 6 or the discharge cylinders 7 to achieve fasterdischarge of water effected by the inclination.

Furthermore, a structure in which the discharge port 3a for the brine ateach drum 3 in the embodiment described above may be formed facingdownward, with the coolant tank connected to the discharge port 3a sothat the brine discharges from the drums 3 is first stored at thecoolant tank before it is returned to the chiller unit 13, may beadopted. This structure, in which the coolant inside the drums 3 flowsdown by gravity to be discharged and stored at the coolant tank when thecirculation of the coolant is stopped, ensures that the coolant and thewater do not come into contact with each other subsequently to preventfreezing.

Moreover, the heat exchangers may be structured so that the flow pathsof the cooling water and the coolant are swapped. For instance, thecoolant may be caused to flow inside pipes provided inside the drums,with cooling water made to travel within the drums outside the pipes. Inthis case, too, it is necessary to ensure that the heat exchangers areemptied of cooling water with the cooling water flowing down into thetank by gravity when the circulation of the cooling water is stopped by,for instance, adopting a structure in which the water discharge ports ofthe drums are provided facing toward the tank. In addition, a structurethat ensures that the coolant flows down into the cooling water tank bygravity to empty the heat exchangers of the coolant when the circulationof coolant is stopped, as described earlier, may be adopted.

Industrial Applicability

As has been explained, according to the present invention, a coolingwater supply apparatus with which it is possible to prevent freezinginside the heat exchangers after stopping the water circulation isprovided.

What is claimed is:
 1. A cooling water supply apparatus comprising:aheat exchanger in which a coolant and water can circulate; and a coolingwater tank for storing cooling water obtained by performing heatexchange between said coolant and circulating water inside said heatexchanger, wherein; said heat exchanger is provided above said coolingwater tank so that when circulation of said water for said heatexchanger is stopped, said water inside said heat exchanger isdischarged to flow down into said cooling water tank; a water dischargeportion and a water intake portion are provided at said heat exchanger;a partition is provided at said cooling water tank to divide the spaceinside said cooling water tank into a first tank and a second tank; saidpartition is formed at a height which allows cooling water to overflowfrom said first tank and to said second tank; said discharge portion isprovided at an upper portion of said first tank so that cooling waterfrom said heat exchanger can flow down into said first tank; and saidsecond tank is connected to said intake portion to allow waterdischarged from said second tank to flow into said heat exchanger.
 2. Acooling water supply apparatus according to claim 1, wherein:a supplypath through which cooling water is supplied to a utilizing facility isconnected to said first tank; and a return path through which coolingwater that has been utilized at said utilizing facility is returned isconnected to said second tank.
 3. A cooling water supply apparatusaccording to claim 2, wherein:said discharge portion is formed in adirection toward said cooling water tank provided below.
 4. A coolingwater supply apparatus according to claim 2, wherein:said intake portionis formed in a downward direction.
 5. A cooling water supply apparatusaccording to claim 1, wherein:said discharge portion is formed in adirection toward said cooling water tank provided below.
 6. A coolingwater supply apparatus according to claim 5, wherein:said intake portionis formed in a downward direction.
 7. A cooling water supply apparatusaccording to claim 1, wherein:said intake portion is formed in adownward direction.
 8. A cooling water supply apparatus provided with aheat exchanger in which a coolant and water can circulate to obtaincooling water by performing heat exchange between said coolant andcirculating water inside said heat exchanger, wherein:a coolant tank fortemporarily storing coolant for which heat exchange with saidcirculating water has been performed inside said heat exchanger isprovided; and said heat exchanger is provided above said coolant tank sothat when circulation of said coolant for said heat exchanger isstopped, said coolant inside said heat exchanger is discharged to flowdown into said coolant tank.